Direct observation of oxygen-vacancy formation and structural changes in Bi₂WO₆ nanoflakes induced by electron irradiation

• Hong-long Shi,
• Bin Zou,
• Zi-an Li,
• Min-ting Luo and
• Wen-zhong Wang

Beilstein J. Nanotechnol. 2019, 10, 1434–1442, doi:10.3762/bjnano.10.141

• stronger than a threshold field, which mainly depends on bond strength or electrostatic site potential of atoms in the crystal. Table 2 lists the electrostatic site potentials of Bi2WO6 calculated by using the VESTA software based on the Fourier method [33]. The oxygen atoms labeled “O4” and “O5” (Figure

Multicomponent bionanocomposites based on clay nanoarchitectures for electrochemical devices

• Giulia Lo Dico,
• Bernd Wicklein,
• Lorenzo Lisuzzo,
• Giuseppe Lazzara,
• Pilar Aranda and
• Eduardo Ruiz-Hitzky

Beilstein J. Nanotechnol. 2019, 10, 1303–1315, doi:10.3762/bjnano.10.129

• samples in Table 2). A remarkable value of 2900 S·m−1 is obtained at 5 wt % of carbon nanotubes, while the percolation threshold for electrical conductivity is at 4 wt % MWCNT content. The conductivity values are higher than the values reported previously for sepiolite–nanocarbon–polymer bionanocomposites

• S·m−1 [52]). The electrical percolation threshold of the foams was around 6.5 wt % MWCNT content. The higher value in foams reflects a poorer connectivity between carbon nanoparticles dispersed in the clay–polymer matrix probably due to the high porosity, requiring a larger amount of GNPs/MWCNTs to

• form a conducting network within the matrix of the bionanocomposite. In any case, the percolation threshold is on par or slightly lower than the values for related MWCNT–polymer composites, which are in the range of 4–9 wt % [56][57]. The bionanocomposite sample Film-1 was used to evaluate the

Molecular attachment to a microscope tip: inelastic tunneling, Kondo screening, and thermopower

• Rouzhaji Tuerhong,
• Mauro Boero and
• Jean-Pierre Bucher

Beilstein J. Nanotechnol. 2019, 10, 1243–1250, doi:10.3762/bjnano.10.124

• spectroscopy (IETS) close to the Fermi level. The differential conductance (dI/dV) spectrum (Figure 2e) reveals a prominent sharp peak close to the zero-bias voltage and two side peaks corresponding to step-like increases in the dI/dV signal (labeled ΔG) at threshold voltages |Vth| = 110 ± 5 meV. This is a

• vibration modes of transition-metal phthalocyanines [29][30], the two steps at |Vth| = 110 ± 5 mV are easily assigned to the excitation of the stretching of the Mn–Niso bonds of the MnPc molecule. The conductance step ΔG at the positive threshold voltage of 110 ± 5 mV, corresponds to an increase in the

• function of the gap resistance in Figure 4a, is a very sharp effect and corresponds to a sudden configurational change of the molecule in the STM gap. Simultaneously, a telegraphic noise appears at bias voltages larger than the side-peak threshold, which is often regarded as the signature of an unstable

Green fabrication of lanthanide-doped hydroxide-based phosphors: Y(OH)₃:Eu³⁺ nanoparticles for white light generation

• Tugrul Guner,
• Anilcan Kus,
• Mehmet Ozcan,
• Aziz Genc,
• Hasan Sahin and
• Mustafa M. Demir

Beilstein J. Nanotechnol. 2019, 10, 1200–1210, doi:10.3762/bjnano.10.119

• material systems such as SrTiO3 [53], Zn2GeO4 [54], La(OH)3:Eu3+ and La2O3:Eu3+ [52] in the literature, is associated with fast crystal growth. A possible cause could be the oversaturation of reactant species. When the concentration of reactive species appears to be higher than the threshold (which may

Electroluminescence and current–voltage measurements of single-(In,Ga)N/GaN-nanowire light-emitting diodes in a nanowire ensemble

• David van Treeck,
• Johannes Ledig,
• Gregor Scholz,
• Jonas Lähnemann,
• Mattia Musolino,
• Abbes Tahraoui,
• Oliver Brandt,
• Andreas Waag,
• Henning Riechert and
• Lutz Geelhaar

Beilstein J. Nanotechnol. 2019, 10, 1177–1187, doi:10.3762/bjnano.10.117

• series resistances as well as the threshold voltages of the single NWs. Finally, we analyze the dependence of the external quantum efficiency (EQE) on the current in single-NW LEDs. By comparing the trends for single and ensemble measurements, we estimate the number of active NWs in the ensemble LED

• point most certainly two NWs are contacted, resulting in half the series resistance compared to that of the single-NW measurements C, E, and G. Another parameter that can be extracted from the I–V behavior is the threshold voltage Vth, which is defined as the zero-crossing of the linear fit function of

• the respective I–V curves. As an example, the dashed line shows the linear fit for NW C. The threshold voltages for the different measurements are shown in Table 1. These values are in agreement with the actual turn-on voltage for which the first EL signal was detected. The comparatively high

Fe₃O₄ nanoparticles as a saturable absorber for giant chirped pulse generation

• Ji-Shu Liu,
• Xiao-Hui Li,
• Abdul Qyyum,
• Yi-Xuan Guo,
• Tong Chai,
• Hua Xu and
• Jie Jiang

Beilstein J. Nanotechnol. 2019, 10, 1065–1072, doi:10.3762/bjnano.10.107

• available. In this work, the shortest pulse has been obtained in a fiber ring laser based on FONPs for the first time. The FONP solution is inserted into a fiber adapter to compose a sandwich structure SA without any polymer, which effectively increases the damage threshold. The modulation depth and the

Revisiting semicontinuous silver films as surface-enhanced Raman spectroscopy substrates

• Malwina Liszewska,
• Bogusław Budner,
• Małgorzata Norek,
• Bartłomiej J. Jankiewicz and
• Piotr Nyga

Beilstein J. Nanotechnol. 2019, 10, 1048–1055, doi:10.3762/bjnano.10.105

• through percolated films to almost continuous films. We found that films below the percolation threshold (transition from dielectric-like to metal-like) made of isolated silver structures provided the largest SERS enhancement of 4-aminothiophenol (4-ATP) analyte signals. The substrate closest to the

• percolation threshold has the SERS signal about four times lower than the highest signal sample. Keywords: metal island film; plasmon resonance; semicontinuous silver film; SERS; surface-enhanced Raman spectroscopy; Introduction Noble metal nanostructures exhibit exceptional optical properties. They can

• the percolation threshold. The sample closest to the threshold has a SERS signal about four times lower than for the highest signal case. Experimental Materials Silver deposition material (99.99%) and BK7 glass substrates were purchased from Umicore. For glass substrates cleaning process, we used

Correlation of surface-enhanced Raman scattering (SERS) with the surface density of gold nanoparticles: evaluation of the critical number of SERS tags for a detectable signal

• Vincenzo Amendola

Beilstein J. Nanotechnol. 2019, 10, 1016–1023, doi:10.3762/bjnano.10.102

• same area probed by Raman spectroscopy. In this way, the minimum number of AuNTs required to generate a detectable signal under ordinary experimental conditions can be identified. In addition, a threshold or minimum number of AuNTs within the probed area that can produce a linear response is identified

• the excitation beam. The results highlight the appreciable intensity of the AuNTs, which allows a clear detection of the Raman signal above the noise threshold with a surface density of only 1 tag/µm2 when using an excitation power of only 0.65 mW at 633 nm with a 50× objective and acquisition times

• as short as 1 s. The tag density can be lowered even below 1 tag/µm2 if the acquisition time can be extended to 10 s, but it should be increased to 3 tags/µm2 with a 20× objective under the same excitation conditions. In case of an ultra-low AuNT density, a threshold of the total number of SERS tags

Direct growth of few-layer graphene on AlN-based resonators for high-sensitivity gravimetric biosensors

• Jimena Olivares,
• Teona Mirea,
• Lorena Gordillo-Dagallier,
• Bruno Marco,
• José Miguel Escolano,
• Marta Clement and
• Enrique Iborra

Beilstein J. Nanotechnol. 2019, 10, 975–984, doi:10.3762/bjnano.10.98

• density and number of graphene layers. We noticed that both lowering the C2H2 flow rates and increasing the overall pressure (up to 12 mTorr) leads to a decrease of the D peak. We also observed that no graphene grows when the overall pressure raises above a given threshold (around 20 mTorr). A more

Electronic properties of several two dimensional halides from ab initio calculations

• Mohamed Barhoumi,
• Ali Abboud,
• Lamjed Debbichi,
• Moncef Said,
• Torbjörn Björkman,
• Dario Rocca and
• Sébastien Lebègue

Beilstein J. Nanotechnol. 2019, 10, 823–832, doi:10.3762/bjnano.10.82

• images. Geometries (cell and atom positions) were relaxed with a threshold on forces of 10−6 eV/Å. The phonon dispersion curves of the single layers, as presented in Supporting Information File 1, were determined with the PHONOPY code [39] with a 5 × 5 × 1 supercell using density functional perturbation

Ultrasonication-assisted synthesis of CsPbBr₃ and Cs₄PbBr₆ perovskite nanocrystals and their reversible transformation

• Longshi Rao,
• Xinrui Ding,
• Xuewei Du,
• Guanwei Liang,
• Yong Tang,
• Kairui Tang and
• Jin Z. Zhang

Beilstein J. Nanotechnol. 2019, 10, 666–676, doi:10.3762/bjnano.10.66

• ; ultrasonication; Introduction Metal halide perovskite nanocrystals (PNCs) are promising candidates for application in the fields of light-emitting diodes (LEDs) [1][2], high-efficiency solar cells [3], low-threshold lasers [4], and photodetectors [5]. Compared to traditional semiconductors, colloidal PNCs

Hydrophilicity and carbon chain length effects on the gas sensing properties of chemoresistive, self-assembled monolayer carbon nanotube sensors

• Juan Casanova-Cháfer,
• Carla Bittencourt and
• Eduard Llobet

Beilstein J. Nanotechnol. 2019, 10, 565–577, doi:10.3762/bjnano.10.58

• depending on whether metallic nanotubes are above or below the percolation threshold [29][30]. In contrast, multiwall CNT mats always present a mild p-type semiconductor behavior which improves device to device reproducibility without the added burden of sorting nanotubes according to their metallic or

Choosing a substrate for the ion irradiation of two-dimensional materials

• Egor A. Kolesov

Beilstein J. Nanotechnol. 2019, 10, 531–539, doi:10.3762/bjnano.10.54

• (TMDs) due to the low displacement threshold barrier [18][19]. The latter is sufficient to create a considerable amount of defects – for example, through initiating a horizontal (in-plane) recoil cascade in a two-dimensional material, which is a chain of successive events of recoil atom energy transfer

• have close values, and therefore the curve components merge. In order to introduce defects into a two-dimensional material, sputtered substrate atoms and recoils reaching the interface need to have enough energy to pass the displacement threshold barrier which shows values from about 4 eV for chalcogen

• also increase the displacement threshold through creating a barrier for displaced atoms of the two-dimensional material, effectively making them “bounce back” after being displaced. For example, the threshold for graphene supported by a common SiO2 substrate increases to 68–196 eV [1], depending on the

Nanocomposite–parylene C thin films with high dielectric constant and low losses for future organic electronic devices

• Marwa Mokni,
• Gianluigi Maggioni,
• Abdelkader Kahouli,
• Sara M. Carturan,
• Walter Raniero and
• Alain Sylvestre

Beilstein J. Nanotechnol. 2019, 10, 428–441, doi:10.3762/bjnano.10.42

• polymers as gate dielectrics presents several advantages for the improvement of the electronic device properties such as higher dielectric constant [35] and dielectric strength [36], reduced threshold voltage [37], increased charge mobility and reduced leakage current [38]. Compared to pure parylene C and

Electromagnetic analysis of the lasing thresholds of hybrid plasmon modes of a silver tube nanolaser with active core and active shell

• Denys M. Natarov,
• Trevor M. Benson and
• Alexander I. Nosich

Beilstein J. Nanotechnol. 2019, 10, 294–304, doi:10.3762/bjnano.10.28

• 2RD, UK 10.3762/bjnano.10.28 Abstract Results from the electromagnetic modeling of the threshold conditions of hybrid plasmon modes of a laser based on a silver nanotube with an active core and covered with an active shell are presented. We study the modes of such a nanolaser that have their emission

• wavelengths in the visible-light range. Our analysis uses the mathematically grounded approach called the lasing eigenvalue problem (LEP) for the set of the Maxwell equations and the boundary and radiation conditions. As we study the modes exactly at the threshold, there is no need to invoke nonlinear and

• quantum models of lasing. Instead, we consider a laser as an open plasmonic resonator equipped with an active region. This allows us to assume that at threshold the natural-mode frequency is real-valued, according to the situation where the losses, in the metal and for the radiation, are exactly balanced

Uniform Sb₂S₃ optical coatings by chemical spray method

• Jako S. Eensalu,
• Atanas Katerski,
• Erki Kärber,
• Ilona Oja Acik,
• Arvo Mere and
• Malle Krunks

Beilstein J. Nanotechnol. 2019, 10, 198–210, doi:10.3762/bjnano.10.18

• ratio exceed a critical value before or during process A, i.e., the energetic threshold for crystallization is surpassed. Absorption coefficient (α) vs wavelength of glass/ITO/TiO2/Sb2S3 samples incorporating as-deposited and vacuum treated (170 °C, 5 minutes) Sb2S3 layers. The α of glass/ITO/TiO2

Sputtering of silicon nanopowders by an argon cluster ion beam

• Xiaomei Zeng,
• Vasiliy Pelenovich,
• Zhenguo Wang,
• Wenbin Zuo,
• Sergey Belykh,
• Alexander Tolstogouzov,
• Dejun Fu and
• Xiangheng Xiao

Beilstein J. Nanotechnol. 2019, 10, 135–143, doi:10.3762/bjnano.10.13

• depth shows linear dependence on the cluster ion dose [8][12][13]. The energy dependence of the sputtering yield of Ag, Cu, Au, and Si exhibits a linear or ultralinear behavior [8][14][15]. In both cases, the energy threshold of 3–6 keV is observed. This value correlates with the surface binding energy

• the residual gas, E is the cluster energy, and Eth is the sputtering threshold energy. The threshold energy has been estimated to be about 6 keV. The same experimental data has also been fitted by the power function without incorporation of the threshold energy [34]: where N is the number of atoms in

• the cluster, A = 57 eV and q = 2.25 are the fitting parameters. At low energy, the denominator is close to 1 and the equation is simplified to The functional dependence in Equation 1 and Equation 3 is the same except for the presence of the threshold energy Eth in Equation 1. In general, the existence

New micro/mesoporous nanocomposite material from low-cost sources for the efficient removal of aromatic and pathogenic pollutants from water

• Emmanuel I. Unuabonah,
• Robert Nöske,
• Jens Weber,
• Christina Günter and
• Andreas Taubert

Beilstein J. Nanotechnol. 2019, 10, 119–131, doi:10.3762/bjnano.10.11

• synthesis temperature. Overall, nitrogen sorption analysis indicates that the porosity does not directly correlate with the synthesis conditions as soon as the threshold temperature of 500 °C is passed. As stated above, a high surface area is a key requirement for a material to work in water treatment. The

Threshold voltage decrease in a thermotropic nematic liquid crystal doped with graphene oxide flakes

• Mateusz Mrukiewicz,
• Krystian Kowiorski,
• Paweł Perkowski,
• Rafał Mazur and
• Małgorzata Djas

Beilstein J. Nanotechnol. 2019, 10, 71–78, doi:10.3762/bjnano.10.7

• /bjnano.10.7 Abstract We report a threshold voltage decrease in a nematic liquid crystal compound, 4-cyano-4′-pentylbiphenyl (5CB), doped with graphene oxide (GO) flakes at a concentration of 0.05–0.3 wt %. The threshold voltage decrease was observed at the same concentration in electro-optic and

• presence of the electric field was discussed. Keywords: graphene oxide; liquid crystal; nematic phase; switching; threshold voltage; Introduction Liquid crystals (LCs) are classified as a type of soft matter which are characterized by anisotropic molecules and a liquid-like fluidity behavior. Of all LC

• Frédericksz effect, the deformation of a homogeneous layer of a NLC is caused by the electric field E, which is initially perpendicular to the director. Such structural transition appears at a certain magnitude called the threshold voltage, Uth. When the applied voltage, U, is lower than the threshold U < Uth

Characterization and influence of hydroxyapatite nanopowders on living cells

• Przemyslaw Oberbek,
• Tomasz Bolek,
• Adrian Chlanda,
• Seishiro Hirano,
• Sylwia Kusnieruk,
• Julia Rogowska-Tylman,
• Ganna Nechyporenko,
• Viktor Zinchenko,
• Wojciech Swieszkowski and
• Tomasz Puzyn

Beilstein J. Nanotechnol. 2018, 9, 3079–3094, doi:10.3762/bjnano.9.286

• also shown relatively low cell viability results, but did not exceed the established toxicity threshold within the test concentration range. HApSA exhibits a toxic effect in the tested range only after having been doped with silicon. Only small differences between the GoHAP hydroxyapatites can be seen

• every figure, a blue line shows the level of control (100% of the living cells after 24 h) and the red line shows the toxicity threshold (50% of the living cells after 24 h). CLSM image of CHO cells and visible GoHAP90s (50 µg/mL) aggregates and agglomerates. A cell is visible a) during ) and b) after

Femtosecond laser-assisted fabrication of chalcopyrite micro-concentrator photovoltaics

• Franziska Ringleb,
• Stefan Andree,
• Berit Heidmann,
• Jörn Bonse,
• Katharina Eylers,
• Owen Ernst,
• Torsten Boeck,
• Martina Schmid and
• Jörg Krüger

Beilstein J. Nanotechnol. 2018, 9, 3025–3038, doi:10.3762/bjnano.9.281

• [22]. In a first set of experiments, LIFT of pure copper with varying layer thickness (10–100 nm) was investigated. The donor layers were irradiated by single pulses with fluences in the range of 0.8–7.8 J/cm2. The threshold for the LIFT decreases with decreasing copper layer thickness. In the case of

Hydrogen-induced plasticity in nanoporous palladium

• Markus Gößler,
• Eva-Maria Steyskal,
• Markus Stütz,
• Norbert Enzinger and
• Roland Würschum

Beilstein J. Nanotechnol. 2018, 9, 3013–3024, doi:10.3762/bjnano.9.280

• depletion of PdHα at a value below −0.99 V is consistent with values reported for palladium thin films [31][32]. The threshold values for the palladium hydride β-phase formation (−0.96 V) and the potential of α-phase depletion (−0.99 V) can be used for a phase distinction in current-controlled experiments

• formation threshold in the fifth loading cycle, which is marked as “onset of PdHβ” in Figure 5. The potential of PdHα depletion was crossed during the 11th loading cycle, which is also indicated in Figure 5. Both strain features present in potentiostatic experiments during desorption, namely the strain

• initiate deformation, this could explain the discrepancies between the mechanical performance of the two variants of npPd. In addition the contribution of dislocation plasticity is avoided when the phase transition proceeds fully coherently. Crossing the threshold potential of PdHβ-phase formation (−0.96 V

Site-controlled formation of single Si nanocrystals in a buried SiO₂ matrix using ion beam mixing

• Xiaomo Xu,
• Thomas Prüfer,
• Daniel Wolf,
• Hans-Jürgen Engelmann,
• Lothar Bischoff,
• René Hübner,
• Karl-Heinz Heinig,
• Wolfhard Möller,
• Stefan Facsko,
• Johannes von Borany and
• Gregor Hlawacek

Beilstein J. Nanotechnol. 2018, 9, 2883–2892, doi:10.3762/bjnano.9.267

• assumed to contribute whose start energy exceeds a displacement threshold of 8 eV. A more detailed discussion is given in Möller et al. [36]. The thermally activated phase separation process was simulated with a kinetic Monte Carlo (kMC) code [27]. Substrate preparation All substrates used in this study

Charged particle single nanometre manufacturing

• Philip D. Prewett,
• Cornelis W. Hagen,
• Claudia Lenk,
• Steve Lenk,
• Marcus Kaestner,
• Tzvetan Ivanov,
• Ahmad Ahmad,
• Ivo W. Rangelow,
• Xiaoqing Shi,
• Stuart A. Boden,
• Alex P. G. Robinson,
• Dongxu Yang,
• Sangeetha Hari,
• Marijke Scotuzzi and
• Ejaz Huq

Beilstein J. Nanotechnol. 2018, 9, 2855–2882, doi:10.3762/bjnano.9.266

• being the exposure dose required to clear out the resist from the centre of the doughnut due to the proximity effect, Qp being the threshold dose required for full clearance of the resist, R1 being the inner radius of the doughnut, α being the standard deviation of the forward-scattered deposited energy

Biomimetic surface structures in steel fabricated with femtosecond laser pulses: influence of laser rescanning on morphology and wettability

• Camilo Florian Baron,
• Alexandros Mimidis,
• Daniel Puerto,
• Evangelos Skoulas,
• Emmanuel Stratakis,
• Javier Solis and
• Jan Siegel

Beilstein J. Nanotechnol. 2018, 9, 2802–2812, doi:10.3762/bjnano.9.262

• below the single pulse ablation threshold, which we have determined experimentally as Fabl = 164 mJ/cm2 (following the method proposed by Liu in [38]). This indicates that the ablation is mediated by incubation and/or heat accumulation at the high repetition rate used [39][40] (a more detailed